Epic 5: Memory management / GC

## Epic 5: Memory management / GC

### Goal: long-running programs don’t leak forever.

- [ ] Pick GC strategy (starting point: mark-and-sweep)
- [ ] Heap allocator:
- [ ] bump pointer allocator initially
- [ ] later: free list / coalescing (optional)
- [ ] GC runtime:
- [ ] mark phase (graph traversal)
- [ ] sweep phase
- [ ] Escape analysis (stack-allocate objects that don't escape the method)
- [ ] Safepoints + root tracking:
- [ ] define safepoints (alloc, call boundaries, loop back-edges, etc.)
- [ ] map stack slots + registers → "this holds an object pointer"
- [ ] Tests:
- [ ] cyclic structures
- [ ] allocation-heavy loops
- [ ] "GC during deep recursion" / stack-heavy programs